Hydration of Tricalcium Silicate in the Presence of Lignosulfonates, Glucose, and Sodium Gluconate

Two commercial calcium lignosulfonates were separated into their main constituents, i.e. fractions high in salts of lignosulfonic acids and fractions high in sugars and sugar‐acid salts. Hydration of C 3 S in the presence of these fractions was studied. The fractions high in sugar acids caused a delay in hydration with a subsequent acceleration of hydration at additions of 0.1%. Fractions high in lignosulfonates caused little delay, whereas additions of 0.5% caused complete inhibition. Hydration was also studied in the presence of glucose and sodium gluconate. Adding 0.1 % glucose delayed hydration for about 11 days, whereas adding 0.1% sodium gluconate caused complete inhibition. The delay in hydration is discussed in terms of poisoning of nucleation sites.